Device for opening and filling an envelope

ABSTRACT

A device for opening and filling an envelope comprises at least two opening members arrangeable to lie in a substantially flat plane so that two layers of plastics film may be sealed together on each side of the members to form a substantially flat envelope containing the members, the members being movable apart to open at least the mouth of the envelope and the device including a pusher device movable to push an article between the members when they are apart and into the envelope.

United States Patent 1 Bate [451 May 6,1975

[ DEVICE FOR OPENING AND FILLING AN ENVELOPE [76] Inventor: Frederick Douglas Clavell Bate, 155

Barkerhouse Rd., Nelson, England 22 Filed: June 25,1973

21 Appl. No.: 373,417

[30] Foreign Application Priority Data June 29, 1972 United Kingdom 30398 [52] U.S. Cl. 53/187; 53/252; 53/258 [51] Int. Cl 1365b 43/34 [58] Field of Search....... 53/29, 183, 187, 258, 252,

[56] References Cited UNITED STATES PATENTS 3,358,414 Hersh et a1. 53/131 X 3,774,367 11/1973 Lerner 53/187 X Primary Examiner-Travis S. McGehee Attorney, Agent, or Firm-Norris & Bateman [57] ABSTRACT A device for opening and filling an envelope comprises at least two opening members arrangeable to lie in a substantially flat plane so that two layers of plastics film may be sealed together on each side of the members to form a substantially flat envelope containing the members, the members being movable apart to open at least the mouth of the envelope and the de vice including a pusher device movable to push an article between the members when they are apart and into the envelope.

19 Claims, 3 Drawing Figures PATENIEBMY 65975 SHEET 3 BF 3 m w T DEVICE FOR OPENING AND FILLING AN ENVELOPE The present invention relates to envelope opening and filling methods and apparatus. The invention has been specifically developed for opening and filling envelopes as part of a shrink wrapping process, in which the envelope itself is made from a heat-shrinkable plastics film, an article is introduced into the envelope and then the envelope is subjected to heat treatment which causes the envelope to shrink tightly on to the article. Although the invention is eminently suitable for the shrink wrapping process, it is to be understood that it can be used in other wrapping or packaging methods.

The expression article is used herein to include not only a single article, but also a collection of articles which are to be wrapped together.

According to the invention a device for opening and filling an envelope comprises at least two opening members arrangeable to lie in a substantially flat plane so that two layers of plastics film may be sealed together on each side of the members to form a substantially flat envelope containing the members, the members being movable apart to open at least the mouth of the envelope and the device including a pusher device movable to push an article between the members when they are apart and into the envelope.

The invention includes a method of opening and filling an envelope comprising arranging at least two opening members lying in a substantially flat plane within the mouth of a substantially flat envelope, moving the opening members apart to open and grip the mouth of the envelope thereby forming a shaped entry throat, and operating a pusher device to push an article between the members, through the entry throat and into the envelope, the article itself opening the remainder of the envelope.

By way of example, a specific embodiment of the invention will now be described, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view showing the general layout of apparatus according to the invention;

FIG. 2 is a perspective exploded view of part of the apparatus, to a larger scale and taken from a different angle; and

FIG. 3 is a plan view of another part of the apparatus, also to a larger scale.

The machine forming the subject of this example is arranged to wrap articles of general prismatic shape, and in the instance shown. the articles are rolls of wallpaper. The rolls should be completely enveloped in heat shrinkable plastics film such as polyvinylchloride, ready for passing through a shrinking zone in which heat is applied to tighten the film on each paper roll.

The machine is arranged to feed two layers 10, 11, of plastics film together, introduce an opening device between the layers and then to seal these layers of film along transversely arranged seals, at longitudinally spaced positions, so that a flat envelope is formed between each pair of adjacent seals, and to sever the film transversely, across the centre of the width of each seal, so that the film becomes divided into separate envelopes 12, each of which is sealed across leading and trailing edges. Preferred means for sealing and severing are disclosed fully in the co-pending Patent Application Ser. No. 341,526 filed March 1973. The series of flat envelopes 12 are capable of being opened at one end for the purpose of receiving the articles which are to be wrapped. It will be appreciated that since the envelopes are formed in the flattened condition, it would be difficult if not quite impossible to insert articles, without first subjecting the envelopes to an opening action.

For this purpose, an opening mechanism is provided, and this comprises a continuous chain conveyor 13 arranged alongside the envelope forming machine, so that the upper run of the conveyor travels alongside the envelopes as they are formed, and at the same linear speed as those envelopes. A series of carriages I4 is provided on the conveyor, and these are so arranged, that each carriage becomes associated with one of the envelopes, as the carriage is travelling along the top run of the conveyor. Since the carriages are identical, it is only necessary to describe one in detail, but it will be understood, that each carriage carries out the same opening function on the succeeding envelopes, as the envelopes travel along the machine. One such carriage is shown in FIG. 2.

Each carriage is supported on a pair of brackets 15, I6. The brackets each have two holes l7, [8 at their lower edge. Spring loaded pins (not shown) are arranged to pass through these holes and through holes in links of the chain conveyor to releasably connect the carriage to the conveyor. The hole 18 is oval to permit limited relative movement between the pins as the chain conveyor passes around the curved end portion of its path, where the spacings between links of the chain vary as the chain curves. The sides of the brackets, 15, 16 are connected together by metal strips, one of which is shown at 19.

Each carriage comprises a lower part 20, an upper part 21, and an opening part 22.

The lower part comprises two inwardly facing channels 23, 24 fitting around rectangular lugs 25 which project from the brackets l5, l6. The right hand ends of the channels (as viewed in FIG. 2) are clamped together by two blocks 26, 27. The lower block 27 has an inverted T-shaped cross-section and the upper block 26 has a T-shaped cross-section portion 28 from which ex tends a rectangular tongue 29. The block 26 fits between the channels and block 27 is bolted to the block 26 to clamp the lower flanges of the two channels between the arms of the two blocks. Rotatably mounted about a vertical axis between block 27 and the tongue 29 is a sprocket wheel 30. A second sprocket wheel 31 is similarly mounted between a block 32 and another block arranged underneath the channels and bolted to block 32. The block 32 and the block bolted thereto are arranged intermediate the ends of the channels and clamp the channels together in a manner similar to blocks 26 and 27.

Mounted around the outside of the channels for sliding movement along the channels are two substantially U-shaped brackets 33, 34. Each channel has on its un derside a downwardly projecting peg 35, 36.

Arranged around the two sprocket wheels 30, 31 is a chain (not shown). One link 37 of the chain has connected thereto an H-section block 38 which embraces the upper flanges of the channels. Another link 39 has connected thereto an H-section block 40 which embraces the lower flanges of the channels. Block 40 has a downwardly projecting peg 41. The links 37, 39 are on opposite runs of the chain and movement of peg 41 in either direction along the channels causes the chain to travel around the sprockets so that the block moves along the channels in the opposite direction.

The upper part 21 of the mechanism is bolted to the block 38 for movement therewith. The upper part 21 comprises an I-I-section elongate block 42 with two T- section elongate blocks 43, 44 bolted in its upper channel and two plates 45, 46 and a rectangular block 47 bolted in its lower channel. The block 47 is bolted to the block 38 of the lower part 20 of the mechanism. Mounted between block 43 and plate 45, for rotation about a vertical axis, is a sprocket wheel 48. Mounted between block 44 and plate 46, also for rotation about a vertical axis, is a second sprocket wheel 49. A chain 50 extends around the sprocket wheels and its tension is adjustable by varying the spacing between blocks 43 and 44, and between plates and 46. The flanges 51 of the blocks 43 and 44 are spaced upwardly from the block 42 and provide a track along which a C-section block 52 is free to slide. The far side of the block 52 (as viewed in FIG. 2) is connected to the chain 50, and one link a of the chain is connected to a bracket 54 secured to the channel 23 of the lower part 20 of the mechanism.

The effect of this is that as the peg 41, and hence the block 38 and the upper part 21 move, the nearest run of the chain 50 remains stationary, causing the far run to move relative to the block 42, running around the sprocket wheels 48, 49 as it does so. Thus the block 52 receives an increment of motion from the movement of the upper part 21 and a further increment of motion due to movement of the far run of chain 50 relative to the block 42, to which run the block 52 is attached. Thus for any given travel of the peg 41, the block 52 travels twice as far.

The block 52 carries an elongate pushing rod 53. Each roll of wallpaper which is fed to the chain con veyor 13 rests on supporting ribs (not shown) on the upper part 21 of the associated mechanism. A disc (not shown) is mounted on the end of the rod 53 for pushing against the end of the roll of wallpaper.

The opening part 22 of each mechanism is supported by two parallel rods 54, which are mounted in holes 55 in the bracket 15.

Slidable on each rod 54 are a first block 55, a compression spring 56, a second block 57, a third block 58 and an elongate tube 59. The rods 54 extend a considerable distance inside the tubes 59 but stop short of the right hand end of the tubes. Two shorter rods 60 are fixed within the right hand ends of the tubes and are interconnected by two cross spars 61. Extending from the spars 61 are two further rods 62 which carry a metal plate 63. The plate as viewed from above, is slightly concave about its longitudinal axis and the ends of the plate are downturned.

Each tube 59 is connected to the adjacent block 58 and carries an upstanding arm 64. Each block 58 carries a further arm 65 and from the four arms a framework is suspended by four downwardly inclined links 66. The framework comprises two elongate metal strips 67 interconnected at the right hand end by two cross members 68. Two rods 69 secured to the cross members 68 support an upper plate 70. The plate 70 is the mirror image of the lower plate 63. The links 66 impart a parallel type of motion to the framework so that if the links are pivoted upwardly the strips 67 rise, remaining parallel to the tubes 59, and the plates 63 and 70 move apart, but remain parallel. The two left hand links 66, each comprise one arm of a cranked lever. The other arm 71 of each lever is connected by a straight link 72 to the associated block 57.

Each block 55 has two pegs 73 on its underside which fit into two holes 74 in one of the U-shaped brackets 33 of the lower part 20 of the carriage. Each block 58 has two similar pegs 75 on its underside for connecting the block to the other U-shaped bracket 34 utilising holes 76 in the bracket. Thus relative movement of the pegs 35, 36 towards one another will cause the blocks 55 to compress springs 56 and urge the blocks 57 towards the blocks 58. This will in turn cause the cranked levers to pivot and will move the plates 63, 70 apart. Any restraint placed upon the movement apart of plates 63 and 70 is compensated by compression of the springs 56.

As each carriage moves along the chain conveyor the pegs 35, 36 and 41 run in cam tracks (FIG. 3) on the body of the conveyor which cam tracks control the operation of the mechanism.

The cam tracks running along the upper part of the conveyor are shown in plan view in FIG. 3. At the start of a cycle the pegs 35, 36, 41 have the position shown in dotted lines in FIG. 3, pegs 35, 36 having been moved to a position adjacent the peg 41 so that blocks 58 and 55 slide along the rods 54 and the plates 63 and 70 project outwardly of the conveyor 13 into the sealing section of the tube forming machine where they are disposed between the film layers prior to the heat seal operation. The two layers of film 10 and 11 are then sealed around the plates 63, 70 of the associated carriage so that the plates lie in the plane of the envelope thus produced. They lie marginally inside the envelope, i.e., only within the mouth of the envelope. The flat envelopes are then severed by the machine into separate items 12.

As the carriage passes along the conveyor in the direction of arrow A as viewed in FIGS. 1 and 3 the cam track for peg 41 moves the peg to the right relative to the direction of motion of the conveyor (to the left as viewed in FIG. 2) and pusher 53 consequently begins to move to the left relative to the direction of motion of the conveyor to engage the roll of wallpaper on the carriage. Shortly afterwards, the peg 35 is moved left towards the peg 36 causing the plates 63 and 70 to move apart opening and gripping the mouth of the envelope.

Gripping is assisted by the upturned lips of the plates 63, 70 and is achieved by creating an excess of movement of peg 35 towards peg 36 in relation to the amount of movement apart of plates 63 and 70 which is allowed by the size of the envelope 12. In other words springs 56 are under compression when the envelope mouth is fully open and the mouth is thus placed under tension. Then both pegs 35 and 36 begin to move right drawing the envelope 12 to the right, and at the same time the peg 41 continues to move to the right so that the pusher moves to the left pushing the roll of wallpaper into the envelope as the envelope is being drawn to the right over the wallpaper. The bracket 16 is cut away at its upper edge to permit passage of the envelope and wallpaper. After the wallpaper has moved through the entry throat formed by the open mouth of the envelope the wallpaper itself opens the remainder of the envelope as it moves into the envelope.

At the point 80 marked in dotted lines in FIG. 3 the chicaning action of pegs 35, 36 and peg 41 has been completed positioning the wallpaper roll centrally in the envelope. At this point the peg 4] begins a return stroke to withdraw the pusher 53 from the envelope while the pegs 35 and 36 follow a straight path. At point 81 the peg 35 begins to move to the right away from the peg 36 and at the point 82 the pusher has withdrawn and the plates 63 and 70 have closed. Thereafter peg 4] continues its travel to the left until it reaches its starting position again at point 83. Pegs 35 and 36 commence moving right again to withdraw the plates 63 and 70 from the envelope and at point 83 the pegs 35 and 36 are arranged at the right hand side of the conveyor. The pegs are returned to their starting positions ready for another cycle by cam tracks on the underside of the machine. The rolls of wallpaper within their envelopes are removed by another conveyor 84 (FIG. 1).

The cam tracks are defined by metal strips bolted to the bed of the conveyor. Where a cam track is pushing one of the pegs against a load it is only necessary to define that side of the track which does the pushing. Thus the track for peg 41, at the beginning and end of a working cycle, is defined by two strips 85, 86. However during the working stroke one strip 87 defines the side of the track pushing the peg to the right as a wallpaper roll is pushed into an envelope, and one strip 88 defines the opposite side of the track during the return stroke as the pusher is pulled out of the envelope to its original position. The cam track for peg 36 is initially defined on both sides by strips 89, 90, then on the left hand side only by strips 91, 92, 93, and finally on both sides again by strips 94, 95. The cam track for peg 35 is also initially defined on both sides, by strips 96, 97; then on one side only by strips 98, 99, 100; on both sides by strips 101, 102 between points 81 and 82', then on one side only by strip 103 and finally on both sides by strip 95 and the edge 104 of the conveyor. The strips are arranged so that their positions are fully adjustable to alter the travel of the parts of the carriages to suit different applications. For example the stroke of the pusher (i.e., the stroke of peg 41) is adjustable to choose the best setting for centralising an article in an envelope, and may be reduced when the articles to be packaged are shorter in length than the wallpaper rolls shown.

The marginal insertion of the opening members (i.e., the stroke of peg 36) is adjustable to achieve the best positioning of the plates 63 and 70 in relation to the size of envelope used. The opening movement of plates 63 and 70 (i.e., the stroke of peg 35 relative to peg 36) is adjustable to achieve the optimum gripping tension in relation to the size of envelope used.

The stroke of the pusher may also be varied by altering the length of one or both of the chains passing around sprockets 30, 31 and 48, 49. The lengths can be varied by adding or removing chain links and adjusting the spacing of the members supporting the sprockets to correct the tension. The plates 63 and 70 may be removed and replaced by opening members of a different size so that a variety of different sized envelopes may be used, or replaced by opening members ofa different configuration depending on the shape of the article being inserted.

For example the plates may be replaced by pins or rods when rectangular, square or other straight-sided articles are involved. The rods may be similar to rods 62 and 69 with the plates 63 and 70 removed. The rods may carry, or be interconnected by, links, flaps or other rods and the rods and/or interconnections may have hinges (e.g. of limited movement) or spring loaded parts such that when the opening members are moved apart the rods and/or interconnections move to define any desired profile, such as a polygon, circle or oval.

The parallel linkages shown may be replaced by any other similar linkage. For example the bell-crank levers may be dispensed with, the links 66 being provided with pinions rotatable by sliding racks. Alternatively the strips 67 and tubes 59 may be interconnected by a scissors or lazy tongs form of linkage.

The sprocket and chain drive may be replaced by a grooved pulley and flexible belt, cable or nylon line form of drive.

I claim:

1. A device for opening and filling an envelope comprising at least two opening members adapted to lie in a substantially planar flat condition between two layers of plastics film forming a substantially flat envelope at least partly containing the members, carriage means on which said members are mounted for movement between said substantially flat condition and a spaced apart condition, means for moving said carriage means in a direction to dispose said opening members while in said flat condition in said envelope, means operable for moving said members apart to open at least the mouth of the envelope, an article pusher device on said carriage means, means for actuating said pusher device to push an article in said direction between the members when they are spaced apart and into the envelope, and means for moving said opening members and the pusher device towards one another when said pusher device is actuated so that as the pusher device pushes an article into the envelope the opening members draw the envelope over the article.

2. An opening device as claimed in claim 1, in which said pusher device is itself movable between the members.

3. An opening device as claimed in claim 1 in which there are two opening members comprising a pair of substantially flat plates.

4. An opening device as claimed in claim 1, in which the members are connected together by a parallel linkage mechanism so that the plates move apart in a direction normal to their plane and remain parallel while moving apart.

5. An opening device as claimed in claim 4, in which the members are movable apart by cam means operably connected to said mechanism.

6. An opening device as claimed in claim 5, in which the pusher is movable by cam means operably connected thereto.

7. An opening device as claimed in claim 6, in which means is provided for moving said carriage means along a path, said cam means comprising stationary cam track means extending along the path.

8. An opening device as claimed in claim 7, in which said opening members are operatively connected with a pair of cam followers running respectively in a pair of stationary cam tracks, relative movement of the followers towards one another under control of said cam tracks causing the opening members to move apart and relative movement of the followers away from one another causing the opening members to move together.

9. An opening device as claimed in claim 8, in which the pusher device is operatively connected with a cam follower running in a stationary cam track, pushing movement of the pusher device to push the article being caused by the action of the cam track on the cam follower as the opening device moves along the said path.

10. An opening device as claimed in claim 9, in which the pusher device is connected to the associated cam follower by gearing such that when an increment of motion is imparted to the follower by the track the dis tance moved by the pusher device in the article pushing direction is greater than the said increment.

11. An opening device as claimed in claim 10, in which the said distance moved by the pusher device in the pushing direction is twice the said increment.

12. An opening device as claimed in claim 10, in which the gearing comprises sprocket wheels and a chain drive.

13. An opening device as claimed in claim 1, in which the opening members are provided with means to grip the mouth of the envelope to facilitate drawing the en velope over the article.

14. An opening device as claimed in claim 13, in which the means to grip the mouth comprises outturned lips on the opening members.

15. An opening device as claimed in claim 1, in which the movement of the opening members towards the pusher device is brought about by a pair of followers connected to the opening members running in a stationary pair of cam tracks.

16. An opening device as claimed in claim 1, in which means is provided whereby the members are movable apart by a variable amount so that envelopes of varying dimensions may be opened out.

17. An opening device as claimed in claim 16, in which the members are connected through a resilient linkage which deforms to automatically adjust the spacing of the members after they are moved apart to suit the size of envelope being opened out, and to put the mouth of the envelope under tension.

18. An opening device as claimed in claim 1, in which the movement of the opening members is controlled by means effective to leave a free path between the members for passage of said article.

19. An opening device as claimed in claim 4 in which said opening members are connected by two parallel linkage mechanisms lying one at each side of the opening members. 

1. A device for opening and filling an envelope comprising at least two opening members adapted to lie in a substantially planar flat condition between two layers of plastics film forming a substantially flat envelope at least partly containing the members, carriage means on which said members are mounted for movement between said substantially flat condition and a spaced apart condition, means for moving said carriage means in a direction to dispose said opening members while in said flat condition in said envelope, means operable for moving said members apart to open at least the mouth of the envelope, an article pusher device on said carriage means, means for actuating said pusher device to push an article in said direction between the members when they are spaced apart and into the envelope, and means for moving said opening members and the pusher device towards one another when said pusher device is actuated so that as the pusher device pushes an article into the envelope the opening members draw the envelope over the article.
 2. An opening device as claimed in claim 1, in which said pusher device is itself movable between the members.
 3. An opening device as claimed in claim 1 in which there are two opening members comprising a pair of substantially flat plates.
 4. An opening device as claimed in claim 1, in which the members are connected together by a parallel linkage mechanism so that the plates move apart in a direction normal to their plane and remain parallel while moving apart.
 5. An opening device as claimed in claim 4, in which the members are movable apart by cam means operably connected to said mechanism.
 6. An opening device as claimed in claim 5, in which the pusher is movable by cam means operably connected thereto.
 7. An opening device as claimed in claim 6, in which means is provided for moving said carriage means along a path, said cam means comprising stationary cam track means extending along the path.
 8. An opening device as claimed in claim 7, in which said opening members are operatively connected with a pair of cam followers running respectively in a pair of stationary cam tracks, relative movement of the followers towards one another under control of said cam tracks causing the opening members to move apart and relative movement of the followers away from one another causing the opening members to move together.
 9. An opening device as claimed in claim 8, in which the pusher device is operatively connected with a cam follower running in a stationary cam track, pushing movement of the pusher device to push the article being caused by the action of the cam track on the cam follower as the opening device moves along the said path.
 10. An opening device as claimed in claim 9, in which the pusher device is connected to the associated cam follower by gearing such that when an increment of motion is imparted to the follower by the track the distance moved by the pusher device in the article pushing direction is greater than the said increment.
 11. An opening device as claimed in claim 10, in which the said distance moved by the pusher device in the pushing direction is twice the said increment.
 12. An opening device as claimed in claim 10, in which the gearing comprises sprocket wheels and a chain drive.
 13. An opening device as claimed in claim 1, in which the opening members are provided with means to grip the mouth of the envelope to facilitate drawing the envelope over the article.
 14. An opening device as claimed in claim 13, in which the means to grip the mouth comprises out-turned lips on the opening members.
 15. An opening device as claimed in claim 1, in which the movement of the opening members towards the pusher device is brought about by a pair of followers connected to the opening members running in a stationary pair of cam tracks.
 16. An opening device as claimed in claim 1, in which means is provided whereby the members are movable apart by a variable amount so that envelopes of varying dimensions may be opened out.
 17. An opening device as claimed in claim 16, in which the members are connected through a resilient linkage which deforms to automatically adjust the spacing of the members after they are moved apart to suit the size of envelope being opened out, and to put the mouth of the envelope under tension.
 18. An opening device as claimed in claim 1, in which the movement of the opening members is controlled by means effective to leave a free path between the members for passage of said article.
 19. An opening device as claimed in claim 4 in which said opening members are connected by two parallel linkage mechanisms lying one at each side of the opening members. 